Legal heir's claim_daughter

My father passed-away without a Will, two years ago. And my brother does not want to give anything to me being a girl; although my father verbally committed to me to gift me some real-estate plots and a house. Recently, I was approached by my parental family, most likely my brother did that, with a letter like an NOC saying that I voluntarily give-up my share in my father’s factory. (My father's factory is worth several hundred crores.) That’s when I realized that my father did not write a Will. I investigated and found out that my brother has taken care of most of the things like cash, and maybe some other properties. I found that my father has 4.3% of shares in the factory in his name. The factory was started by my father in partnership with his younger brother and a friend. I checked the financial documents of the company and came to know that these shares might be worth about 3-3.5 crores. Being a legal heir I assume that i am entitled to one third (I have a brother and mother). And, I want to claim it. Also, my father has left one house (worth 7 crores) and an apartment (worth 70 lakhs). Also, there is another residential-plot ( worth about 3-4 crores) that is in litigation with the seller’s heirs. This house was purchased by my father and his younger brother. Apparently my brother and uncle won that case recently. I know this because when they won the case they wanted me to sign an application so that they could file it in higher court, if needed. Our's being a male-dominated family, girls are regarded as waste! I am pretty sure that my brother would not budge if I just request. Please advice how I should approach this issue and claim my part of the share as my father’s legal heir.